#region Disclaimer / License

// Copyright (C) 2009, Kenneth Skovhede
// http://www.hexad.dk, opensource@hexad.dk
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
//

#endregion Disclaimer / License

using System;
using System.Windows.Forms;

namespace Maestro.Login
{
    /// <summary>
    /// A class that wraps the wait cursor into a disposable class, for use with deterministic disposal
    /// </summary>
    public class WaitCursor : IDisposable
    {
        private Form m_owner = null;
        private readonly Cursor m_oldcursor;

        /// <summary>
        /// Initializes a new instance of the <see cref="WaitCursor"/> class.
        /// </summary>
        /// <param name="owner">The owner.</param>
        public WaitCursor(Form owner)
        {
            //This ensures that nested WaitCursors behave as expected.
            //If we are the outermost WaitCursor, set the cursor
            if (owner.Cursor != Cursors.WaitCursor)
            {
                m_oldcursor = owner.Cursor;
                m_owner = owner;
                m_owner.Cursor = Cursors.WaitCursor;
            }
        }

        #region IDisposable Members

        /// <summary>
        /// Finalizer
        /// </summary>
        ~WaitCursor()
        {
            Dispose(false);
        }
        
        /// <summary>
        /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
        /// </summary>
        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        private void Dispose(bool disposing)
        {
            if (disposing)
            {
                //If we are the the outermost WaitCursor, reset the cursor
                if (m_owner != null && m_owner.Cursor == Cursors.WaitCursor)
                {
                    m_owner.Cursor = m_oldcursor;
                    m_owner = null;
                }
            }
        }

        #endregion IDisposable Members
    }
}
